Biomarker for heart disease could also be indicative of subclinical brain damage

Written by Jonathan Wilkinson

Researchers from The Netherlands have identified an association between heart disease and early-stage brain damage through the protein NT-proBNP. Damage to both the heart and brain can occur at a subclinical stage, even before symptoms can be detected. Therefore, a biomarker for diseases such as stroke and dementia that can be detected in the blood could mean that the correct treatment is administered as early as possible. The results were published in the journal Radiology and used patient data from the Rotterdam Study.
The protein NT-proBNP has already been established as a marker for heart disease; levels in the blood increase in response to cardiac wall stress and decrease as recovery occurs. In addition to this, links between heart disease and brain damage have already been observed. However, how NT-proBNP is associated with other markers of subclinical brain damage such as brain volume and white matter integrity is not known.

Using 2397 participants from the Rotterdam Study, the researchers performed a population-based cohort study to compare serum levels of NT-proBNP with MRI findings. The participants included were community-dwelling middle-aged and elderly non-demented individuals without dementia, stroke or a clinical diagnosis of heart disease.

A clear association was observed between NT-proBNP and brain damage. Meike W. Vernooij (Erasmus MC University, Rotterdam, The Netherlands), lead author of the study, explained the findings: “We found that higher serum levels of NT-proBNP were associated with smaller brain volumes, in particular with smaller gray matter volume, and with poorer organization of the brain’s white matter.” The results highlight the idea that the heart and brain are closely linked, even in presumably healthy individuals.

Possible explanations for this association suggest that decreased blood flow to the brain causes cerebral microvascular damage, or that the function of the blood–brain barrier is being altered in some way, particularly if the inflammatory factors associated with cardiac disease are involved.

Despite these promising findings, at this stage it is too early to say whether NT-proBNP could be used as a marker for early-stage brain damage in the clinic. Vernooij explained: “We cannot rule out that the observed subclinical brain damage led to increased levels of NT-proBNP. However, from a biological perspective, and based on animal studies, it is more likely that cardiac dysfunction affects brain changes rather than vice versa.”

Sources: Zonneveld HI, Ikram MA, Hofman A et al. N-terminal pro-B-type natriuretic peptide and subclinical brain damage in the general population. Radiology doi:10.1148/radiol.2016160548 (2016) (Epub ahead of print);